Depression is the most common co-occurring psychiatric disorder in individuals with substance use disorders (SUD). Depression has been associated with both severity of addiction and poor treatment outcome. Previous attempts at treating major depressive disorder (MDD) in individuals with SUD have been hampered by at least one of three limitations: 1) Failure to integrate the treatment of MDD and SUD in one intervention, causing untreated mood symptoms to lead to substance use, while the substance use contributed to the maintenance of mood symptoms;2) Use of single treatment modalities (e.g., medication alone), also leading to small improvement in most patients;and, 3) Use of complex cognitive interventions requiring highly trained personnel that increase the cost of the interventions and limit their future applicability. The goal of the present application is to start to address this problem. The focus of this Stage Ia proposal is the development and initial testing of a stepped-care model to provide integrated treatment for SUD and MDD. The intervention, which we preliminarily call Substance Use Comorbidity Care: Evidence-Based Stepped Strategies for Depression (SUCCESS-D) will overcome prior limitations by: 1) Providing integrated treatment of SUD and MDD;2) Using behavioral and pharmacological interventions;and, 3) Creating an intervention that is counselor-driven to increase feasibility. The combination of provision of integrated treatment and use of complementary treatment approaches should lead to better mood and substance use outcomes, thus addressing a major unsolved need in the treatment of SUD. The first level of SUCCESS-D, delivered by counselors, will integrate motivational interviewing (MI) and behavioral activation techniques to decrease drug use, promote treatment retention, and reduce depressive symptoms. At the second level, a pharmacological algorithm, the Texas Medication Algorithm for Depression (TMA-D) will be implemented to treat the depressive symptoms of individuals who fail to achieve remission with the first step of SUCCESS-D, while cognitive-behavioral treatment will be offered to those who continue to use substances. It is hoped that this integrated intervention will constitute a more comprehensive and potentially more effective treatment model than currently existing approaches. Data from this study, which will be conducted in a large methadone maintenance clinic and a large drug-free program, will help plan future intervention studies that will use stepped-care models to provide appropriate treatment strategies for substance abuse patients with other co-occurring disorders or in more diverse community-based treatment settings.